In the prior-art printing control method of printers, the printing timing has been decided on the basis of the regular time intervals determined by the carriage travel speed and the printing density (the number of dots per unit distance), with the result that this printing control method is effective only when the carriage travels at a constant speed. In other words, in the prior-art printer, the printing operation is not executed during acceleration or deceleration as immediately after the carriage starts traveling or immediately before the carriage is stopped.
According to the prior-art printing method, it has been necessary to prepare marginal sections over the entire length of the printer for accelerating or decelerating the carriage, and therefore the space efficiency is reduced by that amount. Further, the throughput is decreased because no printing operation is executed during the carriage acceleration and deceleration.
Accordingly, the object of the present invention is to enable a high precise printing without being subjected to the influence of carriage speed, by precisely determining the printing timing even when the carriage travels at non-constant speed as when being accelerated and decelerated.